The present invention is directed to a safety surgical scalpel for medical use, having an automatically retractable blade. The present invention can be applied both to disposable scalpels and reusable scalpels.
Many scalpels presently on the market, both of the single-use and the reusable type, are provided with an exposed fixed or interchangeable blade. The exposed blade of such devices exposes the surgeon and those in the operating theater to the risk of serious diseases, such as HIV or vital hepatitis, since the hand-to-hand passing of the bare blade, often contaminated with the blood of the patient, during surgical procedures can cause accidental injury.
To reduce this risk, several blade protection systems have been proposed. For example, WO-90-11725 describes a surgical scalpel which includes a complex mechanism for moving the sheath relative to the blade, to expose the blade in operation. The complexity of this scalpel renders it unsuitable for disposable applications, as well as resulting in a complex manufacturing process. Similarly, EP217638 describes a highly-specialized and complex instrument. However, even in this instrument, the blade must be changed before use, which in itself creates a dangerous situation. PCT/EP93/01458 describes a disposable scalpel provided with a relatively simple mechanical system for retracting the blade. While this scalpel has some advantages, it still has not been completely successful in terms of the ease of its use, so that further improvement has been desired. Retractable blades have also been considered in the context of hand tools such as utility knives (see U.S. Pat. No. 4,028,758, DE-A-3725294 and B-8801175). Such hand tools bear little relationship to the problems faced in designing a surgical scalpel suitable for use in the operating theater.